FOUNDED in 1949 in the Soviet occupation zone of post-war Germany, the German Democratic Republic (GDR) soon became a focal point for Cold War tensions.

Until it ceased to exist in 1990, after the fall of the Berlin Wall, communist East Germany was characterised by a troubled economy and political repression. Citizens digested a heavy diet of socialist propaganda while the state police maintained control with intimidation and violence.

From today (Friday) the Cornerhouse presents Do Not Refreeze, an exhibition that brings together a group of East German photographers whose extraordinary contribution to European photography has hitherto been "frozen out'' by the Cold War.

The exhibition provides a unique historical panorama of a society which, despite having a population of 17 million, was almost entirely unknown to West Europeans.

These photographers negotiated the omnipresent secret police of the former East Germany to create striking images that are increasingly compared to those of luminaries such as Henri Cartier-Bresson and Dorothea Lange.

Their works use an unforgiving documentary style to convey both the harsh realities and remarkable richness of life behind the Iron Curtain.

The images provide a rare glimpse into everyday life and evoke the claustrophobia, rage, envy and ideological pomp of the Communist era, together with an unexpected sense of exoticism.

Adhering to the mantra of "realism'' - the state-directed creed that defined what was artistically acceptable - these photographers circumvented state censorship to produce the most insightful and openly critical visual arts output in East Germany's 40-year history.

Had they been painters or playwrights, the photographers would have been imprisoned for their brazen portrayals of the underbelly of the socialist experiment.

But as photography was not considered by the authorities to possess the same emotional power as "art'', these artists were not only able to work but sometimes also to publish and exhibit.

Photographers were supposed to deploy their work in the service of the state's ``progressive and collective'' self-image.

Extraordinarily, the GDR's regime tolerated this small group of freelance photographers in spite of their celebration of individual identity rather than the collective socialist identity promoted by official cultural policy.

Curator Matthew Shaul says: "Most East German 'art' was straight propaganda but these photographs stand out not only because they are comparable with the best documentary photography but also because the images seem to be in dialogue with the West.

"Isolated and forced to turn their cameras on their immediate environment, these photographers managed to produce an often subversive visual language in a society that was fanatical about control.

"The images they produced reveal the emotional state of individuals against a background of an incredibly coercive and authoritarian state.

"They also emphasise the fact that for 40 years after the end of the Second World War citizens of East Germany experienced nothing of democracy and had little chance of recovering their hopes and dreams."

Above all, the images on display evoke an austere landscape and expose the often squalid reality of the socialist experiment. But they also reflect the humour and stoicism with which East Germany's citizens dealt with their plight.

Do Not Refreeze: Photography Behind The Berlin Wall runs at the Cornerhouse from April 13 to June 17. Admission is free.